WASHINGTON (Sept. 21, 3 p.m. ET) — A study of more than 3,400 Chinese adults has found no evidence that bisphenol A contributes or exacerbates the development of Type 2 diabetes, as previous animal studies, as well as one secondary analysis of data in humans, have previously suggested.
“We did not find a clear association between bisphenol A and risk for diabetes, nor did we find a clear, monotonic association between bisphenol A and risk for diabetes,” said the researchers in a study published in the Annals of Internal Medicine on Sept. 20.
It is the first large-scale human epidemiologic study that looked at BPA and Type 2 diabetes.
“Our data do not support the previous finding of an association between urinary bisphenol A levels and self-reported type 2 diabetes,” the researchers said in their conclusion.
Several animal studies have indicated that BPA can be an endocrine disrupter.
In addition, a secondary analysis of data in humans conducted by several doctors in the United Kingdom and published in the Journal of American Medical Association three years ago had found that even at doses much lower than the Environmental Protection Agency's lowest observed level of adverse effects, BPA induces insulin resistance.
But the diagnoses of diabetes used in that study were self-reported and also combined with borderline cases of diabetes into a single group. In the Chinese study, participants were given a 75-gram oral glucose tolerance test for diabetes.
BPA has a fast metabolic rate, with a half-life less than 6 hours after oral administration, and urine is considered the body fluid most appropriate for assessment of BPA exposure
The Chinese researchers did add that their study had several limitations. Among them: it did not collect data on socioeconomic status, diet, dietary behaviors, and physical activity, and its diagnosis was based on morning urinary concentrations of bisphenol A, which reflect only recent exposure.
The Chinese study comes on the heels of a recently released EPA-funded study which found that human exposure to BPA is extremely low, and that BPA is efficiently metabolized and rapidly excreted in urine, making it unlikely that BPA could cause health effects.
Nevertheless, 10 states, the city of Chicago and four counties in New York have bans on BPA in baby bottles. In addition, Connecticut this year enacted the first ban in the United States on the use of BPA in thermal printer paper cash register receipts, effective July 1, 2015.
There are three bans globally on BPA in baby bottles—in Europe, Canada and Beijing.
BPA is used to make polycarbonate and epoxy resins. More than 8 billion pounds of BPA are produced worldwide every year.